Sealing machine for electric lamps and similar articles



Jan. 10, 1939.

I G. MULLER ET AL SEALING MACHINE FOR ELECTRIC LAMPS AND SIMILAR ARTICLES Filed April '7, 1957 3 Sheets-Sheet 1 mea o m U t .m w 1mm? 1 Their- Attorngg,

Jan. 10, 1939. G. MULLER El AL SEALING MACHINE FOR ELECTRIC LAMPS AND SIMILAR ARTICLES 5 Sheets-Sheet 2 Filed April '7, 1937 Inventors: Gustav Muller,

Kurt, Wemmann, by flw adwlm Their- Attorney.

G. MULLER ET AL Filed April '7, 1937 3 Sheets-Sheet 3 Inventors: Gustav Muller, Kurt Weinmann,

Th I-r- Attorne g.

Jan. 10, 1939.

SEALING MACHINE FOR ELECTRIC LAMPS AND SIMILAR ARTICLES Patented Jan. io, 193a 2,143,708

UNITED SIT-YATES PATENT OFFICE MACHINE. FOR srrnc'riuo LAMPS AND SIMILAR ARTICLES Gustav Miiller, Blankenfelde, and Kurt Weinmann, Berlin-Grunau, Germany, assignors to General Electric Company, a corporation of New York Application April 7, 1937, Serial No. 135,586

In Germany April 20, 1936 In the drawings, Fig. 1 is a perspective view of a sealing head comprisingour invention; Fig. 2 is a longitudinal section therethrough; Fig. 3is a bottom view of the sealing head; Fig. 4 is a plan view of the bulb holder; Fig. 5 is a side elevation of the gears for operating the bulb holder; and Fig. 6 is a diagrammatic plan view of a portion of the sealing machine.

-Referring to Figs. 1 and 2, the sealing head comprises a pair of telescoping hollow spindles I and 2 having an annular channel 3 therebetween SE LING 6 Claims.

Our invention relates to scaling machines for incandescent lamps and the like and more particularly to a sealing head for said machines.

Sealing machines for electrical incandescent lamps, discharge tubes, and similar devices generally comprise a rotatable turret which is indexed intermittently and which carries a number of rotating sealing heads from oneposition to another. The sealing heads hold a bulb over a stem which is supported on the end of a spindle while burners mounted adjacent thereto heat the bulb neck sufficiently to cause it to seal to the stem. There is anexcess portion of the-bulb neck which sags down and is finally cut from the re.- mainder'thereof by the flames from the burners. According to the present practice, separate bulb holders are provided for each different size of bulb which is supported on the sealing head a specific distance from the stem in each instance. This construction causes considerable inconvenience and loss of time in resetting the machine when bulb sizes are changed. Moreover, a faulty seal often results from too'rapid downward movement of the softened excess portion 'or cullet of the bulb neck.

One of the objects of our invention is to obviate the above stated difficulties by providing bulb supporting-means on the sealing heads adapted to support bulbs of any desired diameter and by providing means for pulling down the bulb neck to cause the separation of the excess portion 'of bulb neck to take place under both the influence of a weight and softening of theseal. For this purpose, according to our invention, a pair of jaws is provided which is mountedon a post on the sealing head and is closed by spring pressure to engage the bulb at its maximum diameter. These jaws, in conjunction with a second pair of jaws mounted therebelow, which is closed on the bulb neck by spring pressure, align the bulb with the spindle of the sealing head and with the stem thereon. The latter jaws, which are mounted on a collar on the post of the sealing head, are moved down with the collar so as to pull down the bulb neck. This downward movement is controlled by a suitable cam. "The cam. is mounted on the. spindle and is turned in several successive operations during indexing of the sealing head to cause the displacement of the jaws to take place by steps, the displacement also being limited by the rate of softening of the bulb neck. Other fe'a tures and advantages of the apparatus of our invent-ion w'll be apparent from the description which follows of one species thereof and from the accompanying drawings.

bulb during the sealing-in process. A housing 5 is mounted on the spindle 2 and is secured thereto by a key 4. The said housing 5 has an upwardly extendinghollow post Ii in which is located a shaft I and a sleeve 8 surrounding said shaft. The shaft I and sleeve 8 carry at their upper ends curved bulb holding jaws 9 and Ill respectively. The said jaws 9and II] are each provided at the inside with two curved holding surfaces allel to the axis of the supporting head. The arms II and I2 of said jaws are clamped to the shaft I and the sleeve 8 by screws I3 and I4 respectively. The jaw I0, together with its arm I2 forms a rigid element while the jaw His linked to its arm II by means of a pin I5. The opening and closing movements of these two jaws over the axis of the spindle is accomplished by means of gear drive located within the housing 5. The said gear drive comprises two gear segments I6, H which are located one above the other (Figs. 2 and 3) and are keyed to the shaft 1 and sleeve 8 respectively. The said segments I6, I1 mesh with the gears I8, I9 respectively (Figs. 3 and 5) which are mounted on studs 20, 2I and mesh with each other. Each gear I8, I9 has a cylindrical hub 22 inside of which is disposed a torsion spring 23. The hollow hub 22 of each gear is covered by a washer 24 which is held in place by a screw 25. engages one end 21 of an angularly curved lever 28 which carries a roller 29 at its other end.

The bulb adjusting clamp for the supporting head consists of two jaws 30, 3I mounted on a collar 32 which is slidably mounted on the post 6. One of the clamp legs, in this case the leg of jaw 3|, is provided with an angular finger 3I Each of the jaws 30, 3| is mounted on a pin 33 in the collar32, the said pins 33 being rotated by torsion springs 33' to close said jaws. Each 9'--9" and Ill'--I[I" respectively, which-are par- The gear segment I6 carries a roller 26 which leg of the jaws 30, 3I is also provided with a short.

through which compressed air is blown into the form outward swing and return of the jaws 3|, 3|). The collar 32 also carries a stop pin 34 and a stop roller 35. The pin 34 normally engages a cam 36 which is concentric with respect to the spindle of the supporting head and is integral with an annular sleeve 31 surrounding said spindle. The said sleeve 31 is connected by means of a link 38 (Figs. 1 and 6) to'an angular lever 39 which is rotatablymounted on a pin in the housing 5 and the end 40 of which projects beyond the said housing.

The upper end of the hollow spindle 2 carries loosely a. nozzle 43 which carries a stem 43' and which has a flange 44 thereon and is provided near its upper end with a number of annularly arranged openings 45 through-which compressed air is admitted to the inside of the bulb. The said nozzle has an internal conical surface 45 which rests on the conical end 48 of the spindle 2. The said spindle 2 is mounted on a turret 5| of the sealing machine by means of ball bearings 49 and a sleeve 50.

At the loading position of the sealing machine the two jaws 9, II] are opened to receive a bulb 52 in position above the spindle 2 of the supporting head (Fig. 2). The said jaws 9, III are opened when the angular lever 28 is rotated by means of a control stop 29 through the engagement of roller 29 with said stop in the direction of the arrow shown in Fig. 3 so that the roller 26 on the gear segment l6, which at this moment is located in the indentation in said lever, is pressed outward through the end 21 of said lever. Upon subsequent rotation of the said angular lever 28 in the opposite direction by another control stop (not shown), the roller 26 on the gear segment I6 is released so that the said segments aremoved toward each other by the gears I8, l9 which are rotated by their springs 23. The said segments l6, l1 cause the shaft 1 and sleeve 8 to be rotated thereby causing the arms |2 with the jaws 9. l0 to be rotated. This closing motion continues until the supporting surfaces of the jaws come in contact with the bulb 52 thereby supporting the bulb at four points. The diameter of the bulb 52 at its maximum periphery is of no importance since the motion of the jaws occurs as a result of the action of. the springs 23.

At this loading position the clamping jaws 30. 3| are also opened by the action of a control element (not shown) ,on the finger 3|. After the bulb is inserted the said finger is released so that the jaws 30, 3| are closed by the action of the springs 33. During this closing motion the said jaws grip the bulb neck and adjust it accurately in the axis of the spindle of the supporting head. During subsequent operating positions of the sealing machine the bulb neck is softened by burners at the point opposite the flange of the stem 43'. Prior to this the collar 32 which carries the jaws 30, 3| is lifted by the engagement of the roller 35 thereon with the cam track 35. (Fig. 2). After the bulb neck has been softened sufiiciently at its sealing point lowering of the jaws 30, 3| takes place. In order to assure that this lowering will take place only when the sealing point of the bulb neck has been sufficiently softened, the jaws 30, 3| are released for brief intervals of time in such a way that they can be lowered only a small amount after each indexing of the heads. The lowering of said jaws 30,

3| is controlled by adjustable stops 40 (Fig. 6)

by causing the sleeve 31' and cam 36 to be rotated. In this way the cam 36 is moved back a small amount each time the leg 40 of lever 39 engages one of the stops 4|! thereby withdrawing its support from the pin 34 on the collar 32 and permitting the said collar, by its weight, to pull said jaws 30, 3| down. However, immediately after the lever 40 leaves a stop 40', the cam 36 is again moved forward, by the action of the spring 31 to re-engage and hold the pin 34 at a lower position so that the collar 32 is lowered only a small amount. In' other words, the lowering of the jaws 30. 3| is divided among several indexing motions of the machine so as to -obtain a uniform drawing down of the bulb neck. The stops 40' are adjusted so as to increase the amount of rotation of the cam 36 with each indexing motion. When the bulb neck has been completely severed by the flames, the excess portion or cullet drops on the flange 44. At the unloading position of the machine the bulb jaws 9, ID are opened when the roller 29 on the lever 28 engages a control stop (not shown), similar to stop 29' in Fig. 2, so as to move'the gear segments I6, I! apart. The jaws 30, 3| are then opened by a control element which engages the finger 3| so that the nozzle 43 may be lifted and tilted by suitable mechanism to remove the cullet thereon.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A head for a sealing machine comprising a rotatable vertically disposed spindle for supporting a stem, a pair of jaws for gripping and holding a bulb, a vertically disposed shaft mounted adjacent to said spindle and having a sleeve thereon, said shaft and sleeve being attached to said spindle so as to rotate therewith about the axis of said spindle, one of said jaws being mounted on said shaft and the other on said sleeve, means for causing said shaft and sleeve to be rotated in opposite directions to open and close said jaws, a vertically movable collar surrounding said shaft and sleeve, a second pair ,of jaws mounted on said collar, means for closing said second pair of jaws to engage the neck of said bulb, said pairs of jaws holding said bulb in axial alignment with said spindle, and means for moving said second pair of jaws downward to draw down the cullet of said bulb neck as it is softened during the sealing process.

2. A head for a sealing machine comprising a rotatable vertically disposed spindle, a housing secured to said spindle soas to rotate therewith, a hollow post extending vertically upward from said housing adjacent to said spindle, a shaft having a sleeve thereon mounted in said hollow post, a pair of jaws mounted one on said shaft and one on said sleeve for gripping and holding a bulb, a pair of gear segments in said housing secured one to said shaft and one to said sleeve, a pair of intermeshing gears in said housing, each of said gears meshing with one of said gear segments, means for causing one of said gear segments to be rotated thereby causing the other gear segment to be rotated in the opposite direction so that said shaft and sleeve are rotated in opposite directions to open or close said jaws, a second pair of jaws slidably mounted on said post for engaging the neck portion of said bulb,

said pairs of jaws holding said bulb in axial. alignment with, said spindle, and means for mov- 3. In a head for a sealing machine, a vertically disposed spindle for supporting a stem, and a pair of curved horizontally disposed spring actuated jaws for gripping and holding a bulb in axial alignment with said spindle, one of said jaws having a separate curved horizontally disposed bulb engagement portion pivotally mounted thereon whereby said jaws are adapted to engage and automatically center bulbs of different diameters.

4. In a head for a sealing machine, a vertically disposed spindle for supporting a stem, and

a pair of curved horizontally disposed spring actuated jaws for gripping and holding a bulb in axial alignment with said spindle, one of said jaws having a separate curved horizontally disposed bulb engagementportion pivotally mounted thereon whereby said jaws are adapted to engage and automatically center bulbs of difierent diameters, said separate portion of said one of the jaws and the other jaw each having vertically extending bulb engagement surfaces thereon.

5. A head for a sealing machine comprising a rotatable verticallydisposed spindle for supporting a stem, a vertically disposed hollow post adjacent said spindle, means for supporting said post and causing it to turn with said spindle, a pair of jaws supported by said post for gripping and supporting a bulb, a collar slidably mounted on said post, a second pair of jaws mounted on said collarfor engaging the neck portion of said.

bulb, said pairs of jaws holding said bulb in axial alignment with said spindle, means for supporting said collar, and means for withdrawing said supporting means so that said second pair of jaws is moved downward to drawdown the cullet of said bulb neck as it is softened during the sealing process.

6. A sealing machine comprising a rotatable turret, a plurality of heads on said turret each comprising a vertically disposed spindle for supporting a stem, a vertically disposed hollow post adjacent said spindle, means for supporting said post and causing it to turn with said spindle, a pair of jaws supported by said post for gripping and supporting a bulb, a collar slidably mounted on said post, a second pair of jaws mounted on said collar for engaging the neck portion of said bulb, said pairs of jaws holding said bulb in axial alignment with said spindle, a cam rotatably mounted on said spindle and engaging and supporting said collar, means adjacent the path of travel of said heads for causing said cam to be rotated a slight amount each time the heads are indexed so as to release said collar and allow said second pair of jaws to move downward to draw down the cullet of said bulb neck as' it is softened during the sealing operation, and spring means for causing said cam to be turned back into engagement with said collar in case said collar has not moved down a sufiicient distance.

GUSTAV MtiLLER. KURT WEINMANN. 

